Boiler governor



May 5, 1931'. J, FISHER I 1,803,324

BOILER GOVERNOR Filed Aug. 15, 1923 lllll HllllH x HIH Patented May 5, 1931 Z- UNITED STATES Para? OFFICE JAMES P, FISHER, or BARTLESVILLE, OKLAHOMA, assienon T0 nonnnrY RESEARCH COMPANY, or NEW YORK, N. -Y., A oonronnrron or DELAWARE BOILER GOVERNOR Application filed August 15, 1923. Serial No. 657,505.

My invention relates to the automatic control of the steam pressure of boilers.

The pressure controlling apparatus for steam boilers which forms the subject matter of the present invention is of the type in which the amount of fuel fed to the boiler furnace is varied automatically in accordance with a pressurevarying with variations in the boiler pressure. Certain apparatus of this type are illustrated and described in the patent to Greenfield, No. 1,428,764, granted July 25, 1922, and in the applications of Benjamin Greenfield, Serial No. 484,141, filed July 12, 1921, and Serial No. 591,691, filed October 2, 1922. In the pressure controlling apparatus described in these applications fuel is fed to a furnace under a low pressure which is developed by means of steam in the boiler. The use of steam for controlling the fuel feeding pressure has given considerable trouble in the practical operation of the above combustion regulating systems, due to the freezing of water in the steam pipes and due to the condensation of steam containing oils and alkaline earths in the steam pipes. Furthermore, operating difficulties have arisen in that the mechanism must be simple in construction and sure and accurate in operation, in order to give satisfaction when applying the invention to the locomotive type boiler used in oil well drilling.

It is the principal object of my invention to provide a system of the type mentioned which shall be capable of automatically maintaining the boiler pressure constant within narrow limits.

Another object of the invention is to provide a pressure regulating apparatus for steam boilers which is simple in construction, reliable in action and which will not get out of order easily.

Further objectsand advantages of my invention will appear from the following der' soription taken in connection with the accompanying drawing in which Fig. 1 is an elevation of a steam boiler equipped with a pressure controlling apparatus according to my invention;

Fig. 2 is a vertical section of a governor according to my invention and appearing in Fig. 1;

Fig. 3'is' a vertical section of a controlling valve appearing in Figrlland governed by the device illustrated in Fig. 2, Fig. 3 being taken looking in the opposite direction from cases,-in practice, either the oil supply or the gas supply wouldbe omitted, but it is often convenient to have two sources of piped fuel so that one maybe used in case the other fails, and my governing system is capable of use with a plurality of'sources of fuel supply and is so illustrated in Fig. 1. In fact, my governing means is capable of use where more than two fuel feeding means are connected to a given boiler.

Associated with the oil pipe 2 is a steam pipe 5 leading'to an atomizing injector 6 for spraying the oil intothefurnace through pipe 7. The oil for the furnace is led from' pipe 2 to the injector 6 through a float feed oil chamber or regulator 8, spout 9, vacuum chamberlO and connections 11. The oil is automatically maintained in the chamber of the regulator 8 at a predetermined level and discharges through spout 9 into chamber 10 at a rate depending on the vacuum in cham-- ber 10, the vacuum in chamber lObeing produced by an aspirating action of theinjector 6 on account of the fact that chamber 10 is connected to the suction side of the injector. However, the apparatus as describedup to this point would increase the supply of fuel to boiler 1 with an increase in steam pressure delivered to injector 6. As the steam for the injector is ordinarily taken from boiler 1, this would produce the undesirable result of increasing the fuel fed tothe furnace with increase of steam pressure in the boiler.

Accordingto my invention, I provide a governor 12 connected to the steam space of boiler 1 by a suitable connection 13, the construction of the governor 12 being illustrated a strainer 156. Parts and 16 are suitably spaced as illustrated to act as an ejector, and the chamber 17 in the casing of governor 12 which encloses the adjacent ends of the members 15 and 16 is connected by a channel 18 with a chamber 19. Chamber 19 is separated from steam chamber 14 previously mentioned by a diaphragm 20, and chamber 19 is also in connection with the atmosphere by way of a valve opening 21a, spring chamber 21, and opening 216 in the wall of the latter. Carried 011 diaphragm in chamber 19 is a plate 23 which co-operates with a circular seat 24 held by flange 22 to act as a valve in restricting the passage of air to the chamber 19. A compression spring 25 is mounted in cham ber 21 with its upper end against an adjustable head 26 and at its lower end against a head 40. The head 40 has a downwardly projecting spindle 41 the lower end of which is pointed as illustrated at 42 and pointed end 42 is seated in socket 43 in the centre of the upper face of plate 23 whereby the thrust of spring 25 is transmitted centrally to plate 23. During the normal operation of the boiler the steam pressure below the governor diaphragm 20 seats the valve plate 23 on the seat 24 against the pressure of the spring 25 so that a partial vacuum will be created in the cham' ber 19 by the flow of steam through the aspirating nozzle 16a. The spring 25 is under such tension that it will hold the valve 23 away from its seat 24 as long as the steam pressure remains below normal pressure, that is, the working pressure at which control of the fuel supply is desired. As long as the valve 23 is away from its seat 24 air from the atmosphere will be drawn through the aspirator by way of a port 21?) in the spring casing 12. Under these conditions the subatmospheric pressure developed in chamber 19is practically negligible and consequently the'governor exercises no control over the fuel feeding devices as will more fully appear hereinafter.

Chamber 19 of the governor is connected by pipes 27 and 27a with the means directly in control of the fuel feeding devices, and the pressure in chamber 19 governs the fuel feeding devices and may also govern the air to the furnace. The means in control of'the fuel feeding devices are preferably of the pneumatically controlled type. The pneumatically controlled means which controls the oil delivery to the furnace is generally indicated at 'and the pneumatically controlled means which controls the gas delivery to the furnace is generally indicated at 36. The pneumatically controlled means 30 includes a diaphragm 29 (see Fig. 3) which extends across an air chamber 28, the upper side of the diaphragm being in communication with the atmosphere as by a port 3041 in its casing. Pipe 27 connects chamber 28 with the governor chamber 19. The under face of the diaphragm 29 is thus subjected to the same pres sure as that existing in the chamber 19, the upper face of the diaphragm 29 being exposed to air pressure through port 30a. The spring 81 resists the air pressure on the upper face of the diaphragm 29. Connected to the diaphragm 29 is a spindle 32 which projects downwardly to a point close to the upper end of the spindle'33 of a valve 34 in the upper part of the chamber 10 which, as previously mentioned, is in communication with the suction side of the oil injector 6. Valve 34 controls ports 34a in communication with the atmosphere through opening 320 in device 32a as illustrated in Fig. 3 and is normally held closed by spring 33a on spindle 33. If now the partial vacuum in chamber 19 reaches a degree at which the atmospheric pressure on diaphragm 29 overcomes the spring 31 and spring 33a, air is admitted to the vacuum chamber 10, through the valve 34 and thus the flow of oil from the oil chamber 8 to the injector 6 will be decreased. In practice, the springs 25, 31 and 33a are so chosen or adjusted that the valve 34 is opened somewhat when the desired normal or average steam pressure existsin boiler 1. Any decrease in the normal steam pressure thereupon allows the governor valve 23 to open whereby the vacuum in the governor chamber 19 decreases due to the inflow of air from the atmosphere through the valve whereupon the springs 31 and 33a in the pneumatically controlled means 30 will force the diaphragm 29 and valve 34, respectively, upwardly. lVhen valve 34 is closed the oil injector 6 exerts its full effect on the oil chamber 8 with the result that full delivery of oil to the furnace is effected. On the other hand, an increase in steam pressure above normal will close the governor valve 23 with the result that a vacuum is made effective in the governor chamber19 and hence also in the chamber 28 of the pneumatically controlled means 30. When the degree of vacuum is sufficient, the valve 34 will open to admit air into the chamber 10 thus reducing the aspirating effect of the oil injector 6 with consequent reduction of flow of oil to the furnace as will now be readily understood.

In a similar way, the governor 12 operates on the gas supply when gaseous fuel is being used in the boiler furnace, as follows: In Fig. 1 is illustrated a gas valve 35 in the gas line 3, this valve being controlled by the pneumatically operated means generally indicated at 36. This means 36 like the means is provided with a diaphragm (not shown) there being a closed chamber above and below the diaphragm, the upper chamber communicating with the outlet side of the gas valve through a pipe 39 in the usual manner and the lower chamber connecting with pipe 27a which, it will be remembered, connects with the governor chamber 19. When vacuum is effective in pipe 27a the valve 35 will close to cut off the flow of gas as will now be readily understood. In pipe 27a is a hand valve 37 for cutting out the gas feeding device when its use is not desired.

The supply of fuel gas will thus be governed by the regulator valve 85 which in turn is controlled by the pressures developed in the governor 12.

The boiler governor 12 which acts to govern the fuel feeding pressure also acts to control the flow of air through the boiler furnace and in such a manner that correspondingly, the air supply will-vary in accordance with the fuel feed, and maintain a substantially perfect combustion within the boiler furnace. In the copending application of Benjamin Greenfield, Serial No. 484,141, filed July 12, 1921, is set forth in detail the principle of operation of a damper motor for controlling the draft through a furnace, whereby it is established that the rate of feed of fuel varies in direct proportion as the rate of flow of air through the boiler furnace varies. This same principle is applied in the present invention by using the pressure in the vacuum chamber 10 for controlling the operation of a motor damper when oil is being burned, and by using the gas pressure in a feedline 38, for controlling a damper motor when gas is being burned. v I I The damper motor for controlling the flow of air through the boiler furnace is substantially the sameas that shown in the application of Greenfield, Serial No. 596,436, filed October '23, 1922. This motor comprises a chamber 40, having a plunger 42 suspended within the chamber 40,. and connected by meansof cylindrical diaphragm 44 with the chamber so as to form a closed compartment in the bottom of the chamber. The plunger 42 is connected by means of'a cable 46 with a sheave wheel 48 mounted on the outer end of a damper shaft 50. Shaft 50 extends through the boiler stack 52 and has aweighted pendulum arm 54 mounted on its free end. The

closed compartment in the top of the chamber 40 is connected by means of a pipe 56 with the 44 is weighted sufficiently by the plunger 42 so that the plunger rests on or near the bottom of chamber 40 except where there is superatmospheric pressure below the diaphragm 44 due to gas introduced through pipe 58 or a subatmospheric pressure above diaphragm44 due to a partial vacuum transmitted through pipe 56. 'IVhen plunger42 is in its lowest position damper 7 0 in stack 52 is, substantially closed. Weights 64 and 66 are mounted respectively on the cable 46 and pendulum 54. Weight 64 gives cable 46 the necessary frictional engagement with sheave 48 and also partially counterbalances plunger 42. Weights 66 also partially counterbalances plunger 42, but its principal function is to cause a gradually increasing resistance to the opening of the damper. Weight 66, accomplishes this by reason of the angle at which arm 54 is set, arm 54 being set so that the counter-balancing effect is a maximum when the damper is closed. In other words, the weight of plunger 42 offers its maximum resistance to the pressure or vacuum on diaphragm 44 when the damper is wide open. A stop 68 is so placed in chamber 40 as to contact with and arrest plunger 42 when the damper 7 0 is fully opened. As the amount of fuel fed to the furnace is increased, the pressure or vacuum developed in the chamber 40 increases also and the plunger 42 moves upwardly to open the damper in the stack and thus control the draft of air through the boiler furnace. By adjusting weights 64 and 66 the position of plunger 42 and damper 70 may be determined for any operating conditions in chamber 40 to provide the right draft for any rate of fuel feed.

It will be noted thatthe variation in pressure in chamber 19 is disproportionate to the variation in the steam pressure of the boiler existing in chamber 14. The variation in the steam pressure acts on the pressure in chamber19 not only on account of changes in the dynamic pressure or aspirating effect of the steam ejector in the lower part of the govern-or casing, but also on account of changes in the throttling action of the valve plate 23, due to the corresponding movement of the diaphragm 20 under changes in the static pressure of the steam. Such a disproportionate change in air pressure due to change in the steam pressure may be called a compounding effect, and it will be understood by those skilled in the art from the foregoing description that a corresponding effect in pressure of the governing fluid acting on the oil, or gas valves or other fuel controlling mechanisms may be effected not only when the steam jet device or the like is used to create a partial vacuum, but also when it is used to create super-atmospheric pressure for controlling the fuel valves or feeding arrangements. The utilization for fuel governing purposes of the compounded effect of changes in the steam pressure permits regulation of the steam pressure within remarkably close limits by means of cheap and simple apparatus which can be entrusted to the ordinary boiler fireman without danger of its getting out of order. The average oil well drill rig boiler equipped with governing apparatus according to my invention automatically maintains its steam pressure within one pound of a given pressure, irrespective of ordinary changes in load.

It is to be understood also that the invention includes arr: ngements in which the diaphragm of the governor is subject not to full boiler pressure but to a pressure proportional to that of the boiler pressure, and it is desired in general to include within the scope of the claims forming part of this application all rearrangements or changes in construction of the apparatus herein described which are mechanically equivalent to those stated in the claims.

lVhile the invention has been described with particular reference to a steam boiler it may be pointed out that the invention is not limited to such application but is useful in other relations where it is desirable to control the delivery of fuel to the furnace in accordance with the heat demands made on the furnace. IVhen the invention is used with a steam boiler, boiler steam will ordinarily be used to operate the air inspirator' but as pointed out in the specification, steam from some other source may be used for this purpose. The main consideration is that the air inspirator should be operated continuously and that the aspirating eifect exercised by the aspirator on the pneumatically controlled fuel feeding devices should be in accordance with the heat demand on the furnace.

It will be understood further that I do not limit myself to controlling fluid fuel by the method and apparatus herein disclosed, but contemplate controlling the rate of feeding fuel to the boiler furnace irrespective of the character of the fuel and/or the type of apparatus directly employed therefor.

Having thus described my invention, I claim 1. In an apparatus for controlling the steam pressure of a boiler, the combination of means for controlling the fire under the boiler, means for governing said controlling means con'iprisiug an air chamber so connected to said controlling means that the air pressure in said chamber governs said controlling means, a diaphragm exposed on one side to the air pressure in said chamber and on the other to the steam pressure of the V boiler, and an air valve mounted with said of a boiler, a steam aspirator supplied by steam from said boiler, a diaphragm subject to the steam pressure of said boiler and a valve controlling the air flow to said aspirator and operated by said diaphragm to restrict the flow of air to said aspirator upon increase of steam pressure, said diaphragm being exposed to said restricted air flow at a point intermediate to said valve and said aspirator, and means for controlling the fire under said boiler governed by the air pressure to which said diaphragm is exposed.

3. In combination, a steam-operated air aspirator, a diaphragm one side of which is continually exposed to the suction of the aspirator and at times to the atmosphere, the other side of the diaphragm being continually subject to the static pressure of the steam on the inlet side of the aspirator, and a valve under the control of the diaphragm adapted to regulate the effect of the aspirator suction on the diaphragm in accordance with variations in steam pressure.

l. In apparatus for controlling the steam pressure of steam generatingmeans by varying the amount of fuel supplied thereto, the combination with an injector connected to a supply of fuel, of a valvearranged on the suction side of the injector, a diaphragm associated with said valve and open to the atmosphere on one side, a device operated by the pressure of the generated steam to produce subatmospheric pressure effective on the other side of said diaphragm, said valve being so adjusted that when a predetermined sub-atmospheric pressure is reached the valve will admit air to the injector.

5. In mechanism for controlling the delivery of fuel to a furnace in accordance with the demands made thereon, the combination of a fuel injector, valve mechanism responsive to pneumatic pressure for controlling the delivery of fuel to the injector, an air aspirator adapted to concurrently draw air from a chamber associated with said valve mechanism and from the atmosphere, and mechanism responsive to the demands made on the furnace for controlling the flow of air from the atmosphere through the aspirator whereby the pneumatic pressure effective on said valve mechanism for operating it may be varied.

6. In an oil burning furnace, means for feeding oil to a burner, means for producing a vacuum which increases proportionately with a decrease in the heat demand on the furnace, and means for utilizing the vacuum thus produced to control the oil supply to said burner.

7. In a boiler governor, a diaphragm subj ect to boiler steam pressure, an aspirator operated by said boiler steam pressure, means forming an air inlet to said aspirator, a valve for controlling supply of air through said inlet, a connection between the valve and said diaphragm, and a housing enclosing all the governor mechanism.

8. In apparatus for controlling combustion in an oil fired steam boiler furnace, the combination of an atomizing injector for supplying oil to the furnace, means including an aspirator for developing a vacuum Which increases with an increase in boiler steam pressure, and means whereby said vacuum is utilized to govern the oil supply to said injector.

In testimony whereof I affix my signature.

JAMES P. FISHER. 

